Turbine construction



June 10, 1947. v. CRONSTEDT EI'AL 3 TURBINE CONSTRUCTION Filed lay 11, 1943 2 Sheets-Sheet 1 v. CRONSTEDT ETAL 2,421,833

I ITURBIVNE cousmuc'nou JIIlI le 10, 1947.

Filed llay 11, 194: z'sneem-sheet 2 Patented June 10, 1947' TURBINE CONSTRUCTION Val Cronstedt, Marlboro, and Walter A. Ledwith, Hartford, Conn., assignors to United Aircraft Corporation, East Hartford, Conn., a corporation of Delaware Application May 11, 1943, Serial No. 486,619

9 Claims. (Cl. 253-69) This invention relates to a gas turbine particularly adapted for use in aircraft.

In earlier turbines, particularly of the'multistage type, th casing has been made in opposed sections separable along lines parallel to the axis of the turbine shaft. These lines of separation are diflicult to seal because of the distortion of row of nozzle-forming guides on each ring.

. I=n assembling a casing made up of a series'of rings, it may be advantageous to have some of the rings split, and a feature of this invention is the positioning of the split rings so that the planes of the splits are out of alignment. This arrange- A ment makes a stronger casing, free from a single line of separation extending the entire length of the casing. 1

The conventional turbine casing built up in opposed sections has split sealing rings mounted in line with the rows of blades on the rotor to reduce the leakage around the outer ends of the blades. A feature of this invention is the mounting of these seals in the form of, rings positioned between adjoining casing rings.

Another feature of the invention is the mounting of a casing, built up of a series of rings, by supports all of which engage a single ring. The invention also involves mounting of the inlet scroll on the casing ring engaged by the supports so that loads on the scroll will be transmitted directly to the supports.

Other objects and advantages will be apparent from the specification and claims, and from the accompanying drawings which illustrate what is now considered to be a preferred embodiment of the invention.

Fig. 1 is a sectional view through the turbine.

Fig. 2 is a sectional view of the turbine casing substantially on the line 2-2 of Fig. l.

The turbine, as shown, includes a casing 4 and a rotor 6 both supported ina housing 8. casing is supported by radially extending pins Ill the sections as they become heated by the driving 2 free to expand lengthwise within the housing. The casing, in the plane of the pins, issmaller than the housing, and clearance I3 is provided at the inner ends of pins ID to permit the casing to expand radially.

Housing 8 has a. head I4 which forms a part of the housing and supports a bearing sleeve 16 for the front end of the turbine shaft l8 integral with rotor 8. At the other end of the turbine rotor, housing 8 has a spider 20 within which is a. bearing 22 for the turbine shaft.- The spider has a. plurality of legs 24 eng g radially positioned pins 28 carried by the housing.

The casing is built up of several rings 28, 30, 32 and 34, each of which has a single row of nozzle-forming guides 36. These rows of guides alternate with cooperating rows of blades 38 on the turbine rotor. Bosses I2 are located in casing ring 30 so that all the supporting pins I0 engage ring 30. r

An intake scroll 40 which directs the driving fluid to the row of nozzles on the first casing ring 28 has an integral flange 42 by which the scroll may be mounted on ring 30, which receives the supporting pins so that any loads on the scroll are transmitted directly to ring 39 and thence to the housing.

Casing rings 30, 32 and 34 aresplit on longitudinal planes and each plane of separation 44, 46 and 4B of the adjoining rings is angularly spaced or staggered with reference to the other planes. The split parts of said ring are held together by clamping bolts 50. When the rings are held together in end-to-end relation by clamping bolts 5|, the tendency of any one of the split rings to separate is prevented by the adjoining casing rings.

Sealing rings 52, which control the leakage of driving fluid around the outer ends of the rows of blades on the rotor, may be positioned between adjoining casing rings. As shown, each sealing carried by the housing and engaging bores in bosses l2 in the casing. These pins are all in substantially the same plane and constitute the sole support for the casing. The casing is. thus ring has a flange extending between adjoining casing ring, and held by the same clamping bolts that hold l'ae casing rings together. Each ring, which may be continuous, has one or more inwardly extending sealing fins 56, the edges of which are close to the periphery of the rows of blades. The sealing rings have laterally extending surfaces 51 which engage surfaces of the casing rings for aligning the adjoining rings.

The end casing ring 34 which extends beyond the center line of the last row of blades on the rotor may have its sealing rings 58 mounted in grooves within the ring. The outer end of this casing ring may carry large diameter expansible in end-to-end engagement, at least some of said rings being split longitudinally, and supporting means for the casing extending between the housing and one of said rings, said supporting means constituting the sole support for the casing.

2. In a turbine construction, a. housing, a casing within the housing comprising a plurality of rings in end-to-end engagement, at least some of said rings being split longitudinally with the lines of separation of adjoining rings angularly spaced from each other, and supporting means for the casing extending between the housing and one of said rings between the end rings,

3. In a turbine construction, a housing, a casing within the housing, and comprising a plurality of rings, each of which has a row of nozzle-forming guides thereon, and means between the housing and casing and engaging with one only of the easing rings between the end rings for supporting the casing within the housing.

4. In a turbine construction, a casing comprising several rings in end to end engagement, supporting means for the casing engaging one of said rings, and an intake scroll for the turbine mounted on the ring with which the supporting means engage.

5. In a turbine construction, a casing comprising several rings in end to end engagement, supporting means for the casing engaging one of the rings betweenthe end rings, and an intake scroll for directing fluid to an end ring, said scroll being connected directly to the ring with which the supporting means engage.

6. In a turbine, a casing comprising several rings in end to end engagement, each ring having a row of nozzle-forming guides thereon, ,a rotor having rows of blades cooperating with the rows of guides on -the casing, and labyrinth seals mounted between adjoining casing rings in alignment with the rows of blades'on the turbine, and means for holding adjoining rings together and for clamping the seal in place.

7. In a turbine construction, a housing, a casing within said housing comprising several rings mounted in end to end engagement, eachring having a row of nozzle-forming guides thereon, a plurality of radially extending pins carried by the housing and engaging with'one of said rings and constituting the sole support for said casing within the housing, and means for holding the rings together.

8. In a turbine construction, a housing, a casing within said housing comprising several rings mounted in end to end engagement,'each ring having a row of nozzle-forming guides thereon, a plurality of radially extending pins carried by the housing and engagin with one of said rings and constituting the sole support for said casing within the housing, and an intake scroll connected directly to the ring with which the radially extending pins engage.

9. In a turbine, a casing comprising several rings in end to end engagement, each ring having a row of nozzle-forming guides thereon, a rotor having rows of blades cooperating with the rows of guides on the casing, and labyrinth seals mounted between adjoining casing rings, each seal having laterally projecting substantially cylindrical concentric surfaces on opposite sides thereof engageable with cooperating substantially cylindrical surfaces on the adjoining rings for aligning said rings with each other.

VAL CRONSTEDT. WALTER A. LEDWITH.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Switzerland Apr. 16, 1929 

